Connectivity Guide

In the above scenario, LACP fallback works as follows:
1 The ToR/server boots up.
2 One of the VLT peers takes care of controlling the LACP fallback mode. All events are sent to the controlling VLT peer for deciding the
port that should be brought up and then the decision is passed on to peer devices.
3 The controlling VLT peer can decide to bring up one of the ports in either the local port-channel or in the peer VLT port-channel.
4 One of the ports, local or peer, becomes active based on the decision of the controlling VLT peer.
5 Now the ToR/server has one port up and active. The active port sends packets to the DHCP/PXE server.
6 After receiving response from the DHCP server, the ToR/server proceeds to boot from the TFTP/NFS server.
7 When the ToR/server is fully loaded with the boot image and congurations, the server starts sending LACP PDUs.
8 When the switch receives LACP PDUs from ToR/server, the controlling VLT peer makes the LACP port to come out of the fallback
mode and to resume the normal functionality.
LACP commands
channel-group
Assigns and congures a physical interface to a port-channel group.
Syntax
channel-group number mode {active | on | passive}
Parameters
• number — Enter the port-channel group number (1 to 128). The maximum number of port-channels is 128.
The maximum physical port/maximum NPU is supported.
• mode — Enter the interface port-channel mode.
• active — Enter to enable the LACP interface. The interface is in the Active Negotiating state when the port
starts negotiations with other ports by sending LACP packets.
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